The trial of Ian Bush, the Ottawa man facing charges of first-degree murder in the 2007 triple homicide of a retired tax judge, the judge's wife and a neighbour, began Monday with jury selection.

Alban Garon, 77, his wife Raymonde, 73, and their friend Marie-Claire Beniskos, 78, were found dead in the Garons's 10th-floor apartment at 1510 Riverside Dr. on Saturday, June 30, 2007.

They had been bound, gagged and beaten.

It was Raymonde Garon's brother who found the bodies and called police that day at about 10:30 a.m. At the time, police said the three were likely slain the day before, on Friday, June 29, between 9 a.m. and noon.

The luxury fenced and gated condominium building was equipped with eight closed-circuit cameras, but the live footage was only monitored by security guards and wasn't recorded.

2014 home invasion leads to break

More than three months later, investigators released a composite sketch of a person of interest. In June 2008, a year after the killings, Ottawa police issued a $100,000 reward for information. The reward was offered again in 2010.

But the break in the case didn't come until years later when a Second World War veteran's home was invaded in the New Edinburgh neighbourhood.

Ernest Côté was alone in his second-floor apartment at 31 Durham Pvt. when, one morning in December 2014, a man claiming to be a City of Ottawa employee asked to be buzzed into the building.

After the suspect was let in he asked Côté for money at his front door, and when Cote refused the suspect forced his way into the apartment, Ottawa police said at the time.

The suspect then tied the elderly man up, put a plastic bag over Côté's head, searched the apartment and fled.

Côté was able to free himself and call police once the suspect had left. He suffered only minor injuries and did not need to be taken to hospital.

The following day, police arrested Bush, who was then 59, and later charged him with attempted murder, robbery with violence, forcible confinement, breaking and entering, and two counts of using a credit card obtained by crime.

Côté has since died of natural causes, but the trial is scheduled to proceed in October.

DNA evidence linked cases, sources say

Two months later, in February 2015, sources told CBC News the three victims in the 2007 slayings had bags over their heads and that DNA was uncovered at the scene.

The sources also said investigators were looking into a possible link between the triple homicide and the home invasion.

Days later, Bush was formally charged with three counts of first-degree murder.